To evaluate training effect, the step exercise was loaded to three mem for nine weeks. Step score, cardiopulmonary functions and blood constituents were measured before, during and after the test exercise (50 cm-step exercise and treadmill running), and were compared with the pre-tranining values. The results were as follows: 1) By the training, Harvard step score increased remarkably, expecially in the early stage of training. 2) The post-training values of maximal oxygen uptake increased very significantly and it seemed to be due to increases of stroke volume and tissue oxygen extraction. 3) After the training, the degree of increase in expired volume was small during the treadmill exercise. 4) By the training, increasing rate of respiratory quotient lessened during the exercise and it was considered to be caused by the decreases of carbohydrate consumption and anaerobic metabolism. 5) The blood cholesterol concentrations were harldy changed with this degree of training. 6) The blood lactate level decreased during the recovery periods and the values of the recovery 0 and 5 minutes decreased remarkably, in comparison with the pre-trained values. The above results suggest that the 9 week-training of the step exercise brings about the enhancement of circulatory functions and tissue oxygen utilization, and changes of food-stuffs used during the exercise.